Semiconductor device, method of manufacturing semiconductor device, and antenna switch module

ABSTRACT

Disclosed is a semiconductor device having a radio frequency switch. Also disclosed are an antenna switch module and a method of manufacturing the semiconductor device. The semiconductor device includes a metal wiring insulating film bonded to a silicon substrate. In the semiconductor device, a crystal defect layer extends into the silicon substrate from a surface of the silicon substrate. Crystal defects are throughout the crystal defect layer. The semiconductor device and an integrated circuit are in the antenna switch module. The integrated circuit in the antenna switch module is mounted with the radio-frequency switch device and the silicon substrate. The method of manufacturing the semiconductor device includes a step of forming crystal defects throughout a silicon substrate. Radiation or a diffusion is used to form the crystal defects. After the step of forming the crystal defects, the method includes a step of implanting ions into a surface of the silicon substrate to form a crystal defect layer.

CROSS REFERENCES TO RELATED APPLICATIONS

This is a Continuation application of application Ser. No. 14/605,374,filed on Jan. 26, 2015, which is a Continuation application ofapplication Ser. No. 14/044,983, filed on Oct. 3, 2013, now U.S. Pat.No. 8,987,866, issued on Mar. 24, 2015, which claims priority toJapanese Patent Application JP 2012-245161, filed with the Japan PatentOffice on Nov. 7, 2012, the entire contents of which being incorporatedherein by reference.

BACKGROUND

The present disclosure relates to a semiconductor device, a method ofmanufacturing such a semiconductor device, and an antenna switch module,and more specifically to a semiconductor device having a radio-frequencyswitch device on an SOI (Silicon on Insulator) substrate, a method ofmanufacturing such a semiconductor device, and an antenna switch module.

In recent years, for antenna switch devices, FETs (Field-EffectTransistors) of compound semiconductors (for example, GaAs) that allowcomplicated switch circuits with reduced power consumption to bemanufactured easily have been utilized.

However, such compound semiconductor FETs have been disadvantageous inthat they may be expensive in themselves, and they may involve highmanufacturing costs for a reason that it is necessary to incorporateperipheral circuits that are fabricated on a separate chip as a module,or for any other reason. It is to be noted that examples of theperipheral circuits may include a DC-DC converter, an IPD (IntegratedPassive Device), and the like.

Consequently, in recent years, the development of antenna switch devicesusing an SOI substrate that enables mixed mounting with a DC-DCconverter circuit that is a silicon-based device to be used as aperipheral circuit has been actively carried forward. The SOI substratehas an advantage of being capable of reducing any parasitic capacitance(depletion layer capacitance) that may be caused due to PN-junction,which ensures to achieve the high-performance antenna switch devicesequivalent to compound-based semiconductors.

However, the SOI substrate has a disadvantage of deterioration in theelectrical characteristics that may be caused due to self-heating of MOStransistors. This self-heating is typically a Joule heat resulting fromchannel resistances, being generated by a current flowing through achannel region when an FET is put in ON state.

In particular, MOS transistors that are fabricated on the SOI substrateare separated from silicon of a support substrate by means of a material(for example, silicon oxide) with the thermal conductivity lower thanthat of silicon by two orders of magnitude or more, and thus any heatarising at a channel region may be hard to be dissipated due to aneffect of silicon oxide directly underneath channels, causing the heatdissipation characteristics to be further deteriorated. It is to benoted that the thermal conductivity of silicon is about 144 [W/(m·K)],while the thermal conductivity of silicon oxide is about 1.1 [W/(m·K)].

Examples of technologies for solutions to disadvantages as describedabove may include some technologies that are disclosed in JapaneseUnexamined Patent Application Publication No. H06-029376, JapaneseUnexamined Patent Application Publication No. H05-343667, and thenonpatent document 1: A. Botula, et al., “A Thin-film SOI 180 nm CMOS RFSwitch Technology”, Silicon Monolithic Integrated Circuits in RFSystems, 2009.

An integrated circuit device that is described in Japanese UnexaminedPatent Application Publication No. H06-029376 includes an n-typesemiconductor layer to be bonded via a silicon oxide film on asemiconductor support substrate, wherein a backside contact trench thatis formed in a manner of running through the silicon oxide film from thebackside of the semiconductor support substrate to reach thesemiconductor layer is formed at a semiconductor support substrateregion on the underside of this semiconductor layer, and a metallicconductive member is embedded into this backside contact trench. Throughthis metallic conductive member, any heat arising on the semiconductorlayer is dissipated.

However, in the technology disclosed in Japanese Unexamined PatentApplication Publication No. H06-029376, a large number of backsidecontact trenches may be necessary when a spacing area for switch devicesthat are formed on the semiconductor layer is large. Accordingly, such atechnology is disadvantageous in that rewiring from the semiconductorsupport substrate side may be difficult for a portion of the backsidecontact trenches, which may make it difficult to reduce a size.

In the technology disclosed in the nonpatent document 1, radio-frequencyswitch elements (source region, drain region, gate oxide film, sourceelectrode, gate electrode, and drain electrode) are formed on an SOIsubstrate where an insulating film and a semiconductor layer are formedin order of precedence on a semiconductor substrate, wherein trenchesrunning through an area as far as the semiconductor substrate are formedat the periphery of the radio-frequency switch elements, and a crystaldefect layer as a damage layer is formed on the semiconductor substratein a manner of, for example, implanting argon onto a semiconductorsubstrate area at the bottom of the trenches using an ion implantingtechnique.

This crystal defect layer traps, that is, recombines any carriersarising within the semiconductor substrate when radio-frequency signalsare applied, which prevents variation in the capacitance of thesubstrate to improve the harmonic distortion characteristics.Additionally, by forming an electrode running through the semiconductorsubstrate from the semiconductor layer, a potential of the substrate isfixed to further enhance the effectiveness of preventing variation inthe capacitance of the substrate.

However, in the technology disclosed in the nonpatent document 1, aregion (crystal defect layer as a damage layer) for trapping anycarriers arising within the semiconductor substrate when radio-frequencysignals are applied is not present directly beneath transistors, whichmakes it difficult to completely suppress variations of carriers.

Further, for a support substrate for the SOI substrate to be used forthe radio-frequency switches, a substrate with quite high resistancevalues may be typically used, and thus there is a disadvantage that theintended effectiveness of an electrode running through the semiconductorlayer and the semiconductor substrate for the purpose of fixing asubstrate potential is reduced. In addition, there is also adisadvantage that manufacturing costs rise due to increased number ofprocesses.

A method concerning improvements of deterioration in the electricalcharacteristics due to self-heating that is disclosed in JapaneseUnexamined Patent Application Publication No. H06-029376 as describedabove, which adopts the backside contact for heat dissipation,dissipates any heat by means of the metallic conductive member. Further,a method concerning improvements of the harmonic distortioncharacteristics that is disclosed in the nonpatent document 1, whichadopts the crystal defect layer on one side of the semiconductorsubstrate, prevents variation in the substrate capacitance by trapping,that is, recombining any carriers that are generated by aradio-frequency field by means of the crystal defect layer to suppressgeneration of the harmonic distortion.

However, in recent years, as technologies for achieving higher-poweredoutputs have been advanced, and the field intensity has beenincreasingly raised, it may be insufficient in some cases to provide thecrystal defect layer on only one side of the semiconductor substrate. Insuch a case, an electron beam irradiation method that allows crystaldefects to be introduced uniformly over a whole surface of the substratemay be helpful, although this has posed a disadvantage that the devicecharacteristics vary due to the influence of a hole trap which is formedin a silicon oxide film.

Examples of disadvantages that have been found in the past may includedrop in threshold voltages of n-channel MOSFETs, rise in thresholdvoltages of p-channel MOSFETs, and rise in polysilicon resistances thatis caused due to introduction of crystal defects.

A technology for a solution to the disadvantage as described above isdisclosed in Japanese Unexamined Patent Application Publication No.H05-343667.

A method of repeating electron beam irradiation and thermal treatmentmore than once that are applied to power device IGBTs (Insulated GateBipolar Transistors) is disclosed in Japanese Unexamined PatentApplication Publication No. H05-343667. In this method, by changing theacceleration voltage and irradiation amount for the electron beamirradiation as well as temperature, time, and the like for the thermaltreatment, it is possible to tailor a crystal defect layer and devicecharacteristics to fit desired characteristics.

SUMMARY

However, the method described in Japanese Unexamined Patent ApplicationPublication No. H05-343667 has posed a disadvantage that it may bedifficult to completely restore devices to status prior to irradiationof electron beams because electron beams are applied directly to thedevices, and if the devices are forced to be restored to original statusthrough a thermal treatment, introduced crystal defects may be recovereddue to heating.

It is desirable to provide a semiconductor device, a method ofmanufacturing such a semiconductor device, and an antenna switch module,capable of preventing any thermal destruction due to self-heating of FETelements in antenna switches to be formed on an SOI substrate forcontrolling high power outputs for radio frequencies, while maintainingexcellent harmonic distortion characteristics.

Disclosed is a semiconductor device having a radio frequency switch.Also disclosed are an antenna switch module and a method ofmanufacturing the semiconductor device. The semiconductor deviceincludes a metal wiring insulating film bonded to a silicon substrate.In the semiconductor device, a crystal defect layer extends into thesilicon substrate from a surface of the silicon substrate. Crystaldefects are throughout the crystal defect layer. The semiconductordevice and an integrated circuit are in the antenna switch module. Theintegrated circuit in the antenna switch module is mounted with theradio-frequency switch device and the silicon substrate. The method ofmanufacturing the semiconductor device includes a step of formingcrystal defects throughout a silicon substrate. Radiation or a diffusionis used to form the crystal defects. After the step of forming thecrystal defects, the method includes a step of implanting ions into asurface of the silicon substrate to form a crystal defect layer.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary, and are intended toprovide further explanation of the technology as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are included to provide a furtherunderstanding of the present disclosure, and are incorporated in andconstitute a part of this specification. The drawings illustrateembodiments and, together with the specification, serve to explain theprinciples of the present technology.

FIG. 1 is a flowchart showing a flow of a method of manufacturing asemiconductor device according to a first embodiment of the presentdisclosure.

FIG. 2 is a cross-sectional view for explaining each step of themanufacturing method illustrated in FIG. 1.

FIG. 3 is a cross-sectional view for explaining each step of themanufacturing method illustrated in FIG. 1.

FIG. 4 is a cross-sectional view for explaining each step of themanufacturing method illustrated in FIG. 1.

FIG. 5 is a cross-sectional view for explaining each step of themanufacturing method illustrated in FIG. 1.

FIG. 6 is a table comparing characteristics of various types of supportsubstrates.

FIG. 7 is a graphic representation of comparison results shown in FIG.6.

FIG. 8 is a flowchart showing a flow of a method of manufacturing asemiconductor device according to a second embodiment of the presentdisclosure.

FIG. 9 is a cross-sectional view for explaining each step of themanufacturing method illustrated in FIG. 8.

FIG. 10 is a cross-sectional view for explaining each step of themanufacturing method illustrated in FIG. 8.

FIG. 11 is a cross-sectional view for explaining each step of themanufacturing method illustrated in FIG. 8.

FIG. 12 is a cross-sectional view for explaining each step of themanufacturing method illustrated in FIG. 8.

FIG. 13 is a cross-sectional view for explaining each step of themanufacturing method illustrated in FIG. 8.

FIG. 14 is a cross-sectional view for explaining each step of themanufacturing method illustrated in FIG. 8.

FIG. 15 is a table for explaining effectiveness of suppressing theharmonic distortion.

FIG. 16 is a flowchart showing a flow of a method of manufacturing asemiconductor device according to a third embodiment of the presentdisclosure.

FIG. 17 is a cross-sectional view for explaining each step of themanufacturing method illustrated in FIG. 16.

FIG. 18 is a cross-sectional view for explaining each step of themanufacturing method illustrated in FIG. 16.

FIG. 19 is a cross-sectional view for explaining each step of themanufacturing method illustrated in FIG. 16.

FIG. 20 is a cross-sectional view for explaining each step of themanufacturing method illustrated in FIG. 16.

FIG. 21 is a flowchart showing a flow of a method of manufacturing asemiconductor device according to a fourth embodiment of the presentdisclosure.

FIG. 22 is a cross-sectional view for explaining each step of themanufacturing method illustrated in FIG. 21.

FIG. 23 is a cross-sectional view for explaining each step of themanufacturing method illustrated in FIG. 21.

FIG. 24 is a cross-sectional view for explaining each step of themanufacturing method illustrated in FIG. 21.

FIG. 25 is a cross-sectional view for explaining each step of themanufacturing method illustrated in FIG. 21.

FIG. 26 is a block diagram for explaining a radio-frequency moduleaccording to a fifth embodiment of the present disclosure.

DETAILED DESCRIPTION

Hereinafter, some example embodiments of the present disclosure aredescribed in the order given below.

(A) First Embodiment (B) Second Embodiment (C) Third Embodiment (D)Fourth Embodiment (E) Fifth Embodiment (F) Summary of ExampleEmbodiments (A) First Embodiment

FIG. 1 is a flowchart showing a flow of a method of manufacturing asemiconductor device according to a first embodiment of the presentdisclosure, and FIG. 2 to FIG. 5 are each a cross-sectional view of asemiconductor device corresponding to each step of the manufacturingmethod illustrated in FIG. 1. Hereinafter, the description is providedalong a flow of the manufacturing method illustrated in FIG. 1.

In the manufacturing method illustrated in FIG. 1, to start with, asilicon substrate 1 as shown in FIG. 2 is prepared that is served as abase for a crystal defect introduction substrate (S110). FIG. 2 is across-sectional view of the silicon substrate 1.

For the silicon substrate 1, a silicon substrate with the oxygenconcentration within a range of about 1×10¹⁵ to about 1×10¹⁷ atoms/cubiccentimeter and the specific resistance within a range of about 100 toabout 1×10⁵ Ωcm that is fabricated in an FZ (Floating Zone) method, or asilicon substrate with the specific resistance within a range of about100 to about 1×10⁵ Ωcm that epitaxially grows silicon on a substratefabricated in a CZ (Czochralski) method or an MCZ(Magnetic-Field-applied Czochralski) method may be used. With asubstrate having a caliber of about eight inches, the substrate of about725 μm in thickness may be considered to be appropriate.

Next, a crystal defect 3 is introduced as a first kind of crystal defect(first crystal defect) on the silicon substrate 1 using an electron beamirradiation method (S120).

It is to be noted that a method of introducing the crystal defect 3 asthe first kind of crystal defect is not limited to the electron beamirradiation, but a method of applying radiation, such as gamma ray andneutron ray, to an ingot or a silicon substrate that is fabricated inthe FZ method, as well as a method of diffusing iron, gold, platinum,and the like that are heavy-metal materials as far as a backside of awafer at high temperature for a long period of time to a siliconsubstrate fabricated in the FZ method may be adopted alternatively. Itis to be noted that, when the neutron ray is to be used in the formermethod, it is desirable to form a part of silicon as p-type in advanceto compensate for the specific resistance because this turns intophosphorus resulting in n-type.

FIG. 3 is a cross-sectional view in a case where the crystal defect 3 isformed on the silicon substrate 1 by applying an electron beam 2 ontothe silicon substrate 1. The crystal defect 3 is a crystal defect thatis introduced uniformly over a whole surface of the silicon substrate 1.

In irradiation of the electron beam, a condition that the crystal defectdensity is within a range of about 1×10¹⁴ to about 1×10¹⁶ pieces/cubiccentimeter may be preferable, and for example, the amount of irradiationof the electron beam may be within a range of about 1×10¹⁴ to about1×10¹⁷ electrons/square centimeter. For the acceleration voltage, arange of about 1 to about 10 MeV may be appropriate. The electron beamto be applied under such a condition runs through the silicon substrate1 easily, thereby forming the crystal defect 3 uniformly on the siliconsubstrate 1.

It is to be noted that, when it is desired to avoid adherence of foreignmaterials and the like in manufacturing of the silicon substrate 1, asingle-layer film or a multilayer film with a thickness within a rangeof about 1.5 nm to about several 10 μm may be formed, prior toirradiation of the electron beam 2, on the front surface of the siliconsubstrate 1 as a film for liftoff of foreign materials (for example,silicon oxide film, silicon nitride film, and the like).

Subsequently, using an ion implantation method or any other techniques,a shallow crystal defect 5 is introduced as a second kind of crystaldefect (second crystal defect) on the silicon substrate 1 (S130).

FIG. 4 is a cross-sectional view in a case where the shallow crystaldefect 5 is formed over a predetermined depth range from the frontsurface of the silicon substrate 1 by further performing the ionimplantation for the silicon substrate 1 onto which the electron beam 2has been applied.

For example, the ion implantation may be performed through irradiationof an inert gas such as nitrogen and argon, carbon, or silicon using anion beam 4 under a condition of the acceleration voltage within a rangeof about 10 KeV to about 2 MeV and the dose amount within a range ofabout 1×10¹⁴ to about 1×10¹⁶ ions/square centimeter. Such a manner formsthe shallow crystal defect 5 with high density in a depth range of about100 nm to several micrometers from the front surface of the siliconsubstrate 1.

Above-described steps fabricate a support substrate 10 illustrated inFIG. 5. The support substrate 10 fabricated in such a manner has thecrystal defect 3 that is formed uniformly over a whole surface of thesubstrate by the electron beam 2.

With effectiveness of this crystal defect 3, it is possible to eliminatevariations in the substrate capacitance that may be caused due to theradio-frequency field without sacrificing any device characteristics atall. Therefore, this makes it possible to resolve an issue of theharmonic distortion that is found in the radio-frequency switch devices.

Further, the support substrate 10 has the shallow crystal defect 5 thatis formed over a predetermined depth range from the front surface of thesubstrate by the ion beam 4 in addition to the crystal defect 3, thatis, a double layer of crystal defect. In other words, a defect densityof a surface in contact with the radio-frequency switch device isincreased. With effectiveness of this double layer of crystal defect, itis possible to suppress the harmonic distortion for a wide dynamic rangefrom a small power output to a large power output.

It is to be noted that, when a liftoff film for removing foreignmaterials is formed, the liftoff film may be eliminated using an etchingtechnique and the like after completion of the steps S110 to S130.

Further, after completion of the steps S110 to S130, a shortage of athermal treatment in an assembly step may be made up by carrying out athermal treatment over a temperature range of about 250 to about 350degrees centigrade to adjust a capability of suppressing the harmonicdistortion.

Further, in this embodiment of the present disclosure, the ionimplantation is performed following irradiation of the electron beam,although the order of these steps may be interchanged in such a mannerthat the step S120 is preceded by the step S130. In this case, theshallow crystal defect 5 that is formed using the ion beam 4 isrecrystallized in a polysilicon state through a thermal treatment over atemperature range of about 500 to about 1050 degrees centigrade, andthereafter the uniform crystal defect 3 is formed over a whole surfaceof the silicon substrate 1 including a depth direction using the ionbeam 2.

FIG. 6 is a table comparing characteristics of existing SOI substrates,and FIG. 7 is a graphic representation of this comparison result as wellas characteristics of the support substrate 10. As shown in FIG. 7, thesupport substrate 10 according to this first embodiment of the presentdisclosure is not inferior in characteristics to a sapphire substratethat has typically exhibited excellent thermal conductivity anddielectric tangent characteristics, and a possibility that the supportsubstrate 10 according to this first embodiment of the presentdisclosure will be a material exceeding the sapphire substrate issuggested provided that a capability of suppressing the harmonicdistortion is improved.

(B) Second Embodiment

Next, the description is provided on a second embodiment of the presentdisclosure. The second embodiment relates to a semiconductor device thatis provided with external terminals configured by rewiring on the frontsurface of a radio-frequency switch device using an SOI substrate insuch a manner that an original support substrate for the SOI substrateis removed after bonding a crystal defect introduction substrate on thefront surface of the radio-frequency switch device, as well as to amethod of manufacturing such a semiconductor device.

FIG. 8 is a flowchart showing a flow of a method of manufacturing thesemiconductor device according to the second embodiment of the presentdisclosure. FIG. 9 to FIG. 13 are each a cross-sectional view forexplaining each step of the manufacturing method illustrated in FIG. 8.Hereinafter, the description is provided along a flow of themanufacturing method illustrated in FIG. 8.

In the manufacturing method illustrated in FIG. 8, to start with, an SOIsubstrate is prepared (S210).

FIG. 9 shows a cross-sectional view of a typical SOI substrate in usefor the radio-frequency switch device. For a support substrate 11 forthe SOI substrate, a single-crystal CZ silicon substrate may betypically used in case of a substrate with a caliber of about eightinches. A CZ silicon substrate in use for the support substrate 11 maytypically have a planar direction of (100), a film thickness of about725 μm, a specific resistance within a range of about 500 to about 5000Ωcm, and an oxygen concentration within a range of about 5×10¹⁷ to about5×10¹⁸ atoms/cubic centimeter.

On the support substrate 11, a silicon oxide film is laminated as aburied oxide (box) layer 12 for the SOI substrate. This silicon oxidefilm electrically insulates the support substrate 11. The box layer 12may typically have a film thickness within a range of about 50 to 1000nm.

Further, on the box layer 12, a top silicon layer 13 for the SOIsubstrate on which active elements and the like are formed is laminated.For the top silicon layer 13, a single-crystal CZ silicon substrate maybe typically used. A CZ silicon substrate in use for the box layer 12may typically have a planar direction of (100), a film thickness withina range of about 100 to about 5000 nm, a specific resistance within arange of about 1.0 to about 50 Ωcm, and an oxygen concentration within arange of about 5×10¹⁷ to about 5×10¹⁸ atoms/cubic centimeter.

Subsequently, a radio-frequency switch device is formed on the SOIsubstrate (S220).

FIG. 10 shows a cross-sectional view of a radio-frequency switch deviceaccording to this embodiment of the present disclosure. Theradio-frequency switch device according to this embodiment of thepresent disclosure is finished up in a manner of using a typical SOIsubstrate as described above, and performing a wafer process ofsingle-layer polysilicon and three-layer metal wires using, for example,a minimum line width rule of about 0.25 μm.

As shown in FIG. 10, the radio-frequency switch device according to thisembodiment of the present disclosure may typically include: MOSFETcomponent parts including an element separation layer 14, a drain region15, a source region 16, a gate electrode 17, and a gate insulating film18; multilayer wiring component parts including a metal wiringconnection plug 19, a first metal wiring layer 20, a second metal wiringlayer 22, a metal wiring connection plug 21 between the first metalwiring layer 20 and the second metal wiring layer 22, a third metalwiring layer 24, and a metal wiring connection plug 23 between thesecond metal wiring layer 22 and the third metal wiring layer 24; and aprotective film including a metal wiring insulating film 25.

A layer including the element separation layer 14, the drain region 15,the source region 16, the gate electrode 17, and the gate insulatingfilm 18 corresponds to a specific but not limitative example of an“element layer” in one embodiment of the present disclosure, and a layerincluding the metal wiring connection plug 19, the first metal wiringlayer 20, the second metal wiring layer 22, the metal wiring connectionplug 21 between the first metal wiring layer 20 and the second metalwiring layer 22, the third metal wiring layer 24, the metal wiringconnection plug 23 between the second metal wiring layer 22 and thethird metal wiring layer 24, and the metal wiring insulating film 25corresponds to a specific but not limitative example of a “wiring layer”in one embodiment of the present disclosure.

It is to be noted that, as described later, because the supportsubstrate 11 for the SOI substrate may be removed after bonding of acrystal defect introduction substrate, or may be replaced with thecrystal defect introduction substrate, use of an inexpensive supportsubstrate 11 may be permitted if it is capable of withstanding a waferprocess.

Next, the crystal defect introduction substrate is bonded against thetop-front surface of the radio-frequency switch device (S230).

FIG. 11 is a cross-sectional view in a case where the crystal defectintroduction substrate is bonded against the top-front surface of thefinished radio-frequency switch device. This figure illustrates a statewhere the support substrate 10 that is fabricated in the above-describedfirst embodiment of the present disclosure is bonded against thetop-front surface of the radio-frequency switch device using an adhesiveagent 31.

Preferably, the adhesive agent 31 in use for bonding may have acapability of permanently bonding the support substrate 10 with theradio-frequency switch device, as well as a dielectric tangent (tan δ)of the radio-frequency characteristics within a range of about 0.0001 toabout 0.01, and a film thickness within a range of about 50 to about1000 nm, and a candidate example for such an adhesive agent may includesiloxane-based benzocyclobutene (BCB). After bonding of the supportsubstrate 10, an adhesive force may be preferably stabilized byperforming a thermal treatment over a temperature range of about 100 toabout 350 degrees centigrade.

It is to be noted that, in this second embodiment of the presentdisclosure, the support substrate 10 is bonded using the adhesive agent31, although a bonding method is not limited thereto, but a directbonding without using an adhesive agent may be also permitted afterplanarizing the front surface by performing a polishing work in a CMP(Chemical Mechanical Polishing) method or a BGR (Back Grind) method.

As described above, by bonding the support substrate 10 against thetop-front surface of the radio-frequency switch device, theradio-frequency switch device is located in proximity to the surface onthe side opposite to the side coming in contact with the supportsubstrate 10 on a semiconductor layer.

On this occasion, a distance between the MOSFET as the radio-frequencyswitch device and the support substrate 10 is longer than a distancebetween the MOSFET and the original support substrate 11 for the SOIsubstrate, that is, a distance between the support substrate 11 and theMOSFET may be approximately equivalent to a thickness (about 1 μm) ofthe box layer 12, while a distance between the support substrate 10 andthe MOSFET may be in the order of about 10 μm.

In such a manner, separation of the MOSFET from the support substrate 10allows the harmonic distortion to be reduced, and an experimentdemonstrated the improvement effect of about 10 dB in the harmonicdistortion. Further, a distance between the MOSFET and the supportsubstrate 10 is, unlike a thickness of the box layer 12, allowed to becontrolled optionally to some extent, which facilitates reduction of theharmonic distortion.

The next step removes the support substrate 11 that is the originalsupport substrate for the SOI substrate (S240).

FIG. 12 is a cross-sectional view in a case where the support substrate11 for the SOI substrate is removed to expose the box layer 12 on theSOI substrate. A support substrate removal area 32 illustrated in FIG.12 represents the support substrate 11 that is exfoliated or eliminated.

The support substrate 11 for the SOI substrate may be removed by apolishing work in the CMP method, a grinding work in the BGR method, ora wet etching process using a chemical solution such as a nitricfluoride-based solution. For example, it is possible to remove thesupport substrate 11 from the SOI substrate without damaging the boxlayer 12 in such a manner that the support substrate 11 is ground to thedegree where a piece of membrane is left in the vicinity of a boundarywith the box layer 12 in the CMP or BGR method, and the rest of thesupport substrate 11 is removed in a wet etching process. It is to benoted that, in this state, a device pattern of the radio-frequencyswitch device is allowed to be observed optically from a surface onwhich the support substrate 11 for the SOI substrate has been present,that is, a surface on which the box layer 12 is exposed.

The subsequent step provides external terminals by performing rewiringon the front surface at the side where the original support substratefor the SOI substrate is removed (S250).

FIG. 13 is a cross-sectional view in a case where a rewiring insulatingfilm 33 and a metal wiring connection trench 34 are formed on thesurface of the box layer 12 of the SOI substrate.

Preferably, the rewiring insulating film 33 may be a silicon nitridefilm with a film thickness within a range of about 100 to about 5000 nm,and may be formed in a method such as a plasma CVD that is capable ofgenerating the film over a temperature range from room temperature toabout 300 degrees centigrade. Following formation of the rewiringinsulating film 33, the metal wiring connection trench 34 for rewiringwith a diameter within a range of about 5 to 100 μm is etched as far asthe first metal wiring layer 20 using lithography and dry etchingtechniques, thereby exposing the first metal wiring layer 20.

FIG. 14 is a cross-sectional view showing a final form of the secondembodiment of the present disclosure. To achieve this final form, as afirst step, a clean surface of the first metal wiring layer 20 that islocated at the bottom of the metal wiring connection trench 34 isexposed using a reverse sputtering of argon or any other techniques, todeposit a titanium film with a thickness within a range of about 10 toabout 200 nm in a sputtering method, and a copper film 35 with athickness within a range of about 50 to about 500 nm is deposited in thesputtering method to form an electrode for copper plating.

Thereafter, rewiring is carried out using a lithography technique. Aline width for this rewiring may be within a range of about 5 to 100 μm.Any region to be excluded from the rewiring is electrically insulatedwith a photosensitive organic film, such as a resist film and a filmmembrane, and a metallic copper film 35 is precipitated with a thicknesswithin a range of about 1 to 10 μm in an electrolytic method to platethe metallic copper 35 at a portion to be rewired.

Further, when the photosensitive organic film that is formed using thelithography technique and the titanium film that is formed in thesputtering method are removed in turn utilizing a wet or dry etchingtechnique, a rewiring metal wiring layer 35 with a film thickness withina range of about 1 to 10 μm and a line width within a range of about 5to 100 μm is formed.

Subsequently, photosensitive polyimide is coated as a rewiringprotective film 36, and a pilot hole of solder ball 37. The solder ball37 along with other solder balls form a BGA (Ball Grid Array). Thesolder ball 37 for a chip electrode is drilled using the lithographytechnique to perform curing under a nitrogen atmosphere for about 60minutes over a temperature range of about 250 to about 300 degreescentigrade.

Finally, an organic insulating film that is formed by curing inside thepilot hole of the solder ball 37 for the chip electrode is removed inthe dry etching technique such as an oxygen plasma method, and thesolder ball 37 for the chip electrode is formed on a clean surface ofthe metallic copper 35. Such a step brings the rewiring illustrated inFIG. 14 to completion.

It is to be noted that, in the second embodiment of the presentdisclosure, the rewiring is made at the box layer 12 side of the SOIsubstrate, although an insulating film may be formed as a protectivefilm on the box layer 12 side of the SOI substrate to make rewiringthrough a TSV (Through Silicon Via) that is formed at the supportsubstrate 10 side.

In the semiconductor device that is fabricated in the above-describedsteps, even if carriers, such as holes and electrons, should occur onthe support substrate 10 when a radio-frequency signal flows throughwiring for transmitting control signals to the MOSFETs, such carriersmay disappear before reaching the vicinity of a boundary with the metalwiring insulating film 25 over a lifetime of the crystal defect that isintroduced in the support substrate 10.

Accordingly, this prevents aggregation of carriers on the front surfaceof the substrate, and prevents occurrence of capacitance between thewire and the support substrate 10. Therefore, this has an effect ofreducing variations in the substrate capacitance that may be caused dueto a harmonic field arising during switching operation.

FIG. 15 is a table for explaining effectiveness of suppressing theharmonic distortion in the semiconductor device according to the secondembodiment of the present disclosure. For a signal intensity for each ofsecond harmonics and third harmonics that are generated whenradio-frequency signals (for example, several gigahertz signals) areinput at a power of about 35 dBm, this table shows a result of comparinga case of using a support substrate with the electron beam irradiationand a case of using a support substrate with no electron beamirradiation.

As shown in this table, it was found that when the support substratewith the electron beam irradiation was used, the intensity wasattenuated by about 20 dB for the second harmonics, and was attenuatedby about 25 dB for the third harmonics as compared with the supportsubstrate with no electron beam irradiation. It is to be noted that atest cited in this table used a support substrate onto which theelectron beam was applied under an irradiation condition of about 4.6MeV and 504 kGy as the support substrate with the electron beamirradiation.

Further, to bond the support substrate 10 against the surface on theside where the MOSFET is formed, a very thin box layer is onlyinterposed between the MOSFET and a silicon layer on the supportsubstrate 10.

Here, because the MOSFET mainly generates heat among radio-frequencyswitch devices, and silicon is higher than an oxide film in the thermalconduction coefficient, a structure ensuring to further facilitate heatdissipation as compared with an existing one is achieved. Additionally,it is possible to transfer heat to a printed circuit board on which theswitch device element is mounted through conduction via a metal of thesolder ball 37 and ambient air, which further improves the heatdissipation effect.

(C) Third Embodiment

Next, the description is provided on a third embodiment of the presentdisclosure. A semiconductor device according to the third embodiment ofthe present disclosure is provided with external terminals configured byrewiring on the front surface of a radio-frequency switch device usingan SOI substrate in such a manner that an original support substrate forthe SOI substrate is replaced with a crystal defect introductionsubstrate after bonding a temporary support substrate against the frontsurface of the radio-frequency switch device, and thereafter thetemporary support substrate is removed. Hereinafter, the description isprovided on an example of a manufacturing method and a structure of sucha semiconductor device.

FIG. 16 is a flowchart showing a flow of a method of manufacturing thesemiconductor device according to the third embodiment of the presentdisclosure. FIG. 17 to FIG. 20 are each a cross-sectional view forexplaining each step of the manufacturing method illustrated in FIG. 16.Hereinafter, the description is provided along a flow of themanufacturing method illustrated in FIG. 16.

It is to be noted that, because examples of a structure and amanufacturing method using a typical SOI substrate to be used for theradio-frequency switch device after completion of a wafer process aresame with cases in FIGS. 9 and 10 that are explained in theabove-described second embodiment of the present disclosure, anycomponent parts essentially same as those of such cases according to thesecond embodiment are denoted with the same reference numerals, and thedetailed descriptions are omitted as appropriate.

In the manufacturing method shown in FIG. 16, bonding of a temporarysupport substrate and removal of an original support substrate arecarried out after performing steps S310 and S320 similar to the stepsS210 and S220 according to the above-described second embodiment of thepresent disclosure (S330).

FIG. 17 is a cross-sectional view in a case where the support substrate11 for the SOI substrate is removed after bonding a temporary supportsubstrate 42 against the top-front surface of the finishedradio-frequency switch device. It is to be noted that this figureillustrates the removed support substrate 11 as a support substrateremoval area 43.

As a material for the temporary support substrate 42, a material withless warpage that may be caused due to its own weight or a stress, suchas silicon, ceramic, and quartz may be preferable. For a substrate witha caliber size of about eight inches, a thickness within a range ofabout 100 to about 1500 μm may be suitable. Further, from a viewpoint ofprevention of any lack in adhesive uniformity, the planar property ofthe temporary support substrate 42 may be preferably equivalent to thatof a mirror wafer of a silicon substrate.

The temporary support substrate 42 is bonded temporarily using atemporary adhesive agent 41. For the temporary adhesive agent 41, anytype that is allowed to be easily peeled off using heat or light may besuitable. A type to be peeled off using heat may be suitable when amaterial for the temporary support substrate 42 is hard to transmitlight therethrough like silicon and ceramic materials, and a type to bepeeled off using light may be suitable when the material for thetemporary support substrate 42 is easy to transmit light therethroughlike a quartz material. Preferably, the temporary adhesive agent 41 mayhave a film thickness within a range of about 100 nm to about 10 μm.

The support substrate 11 that is an original support substrate for theSOI substrate is removed by a polishing work in the CMP method, agrinding work in the BGR method, or a wet etching process using achemical solution such as a nitric fluoride-based solution. At thisstage, the box layer 12 on the SOI substrate at the backside of thedevice is exposed.

Subsequently, the original support substrate is replaced with thecrystal defect introduction substrate to which the first kind of crystaldefect is introduced, and the temporary support substrate is removed(S340).

FIG. 18 is a cross-sectional view showing a state where the temporarysupport substrate 42 and the temporary adhesive agent 41 are removedafter replacing the support substrate 11 with the support substrate 10.This figure denotes removal traces of the temporary support substrate 42and the temporary adhesive agent 41 as a temporary support substrateremoval area 45 and a temporary adhesive agent removal area 46,respectively.

The support substrate 10 is bonded against the box layer 12 using anadhesive agent 44. Preferably, the adhesive agent 44 may have adielectric tangent (tan 6) of the radio-frequency characteristics withina range of about 0.0001 to about 0.01 and a film thickness within arange of about 50 to about 1000 nm to ensure permanent bonding, and acandidate example for such an adhesive agent may include siloxane-basedbenzocyclobutene (BCB).

It is to be noted that, in this third embodiment of the presentdisclosure, the support substrate 10 is permanently bonded against thebox layer 12 at the backside of the radio-frequency switch device usingthe adhesive agent 44, although a bonding method after exposure of thebox layer 12 is not limited thereto, but a direct bonding without usingan adhesive agent may be also permitted by performing a grinding work inthe CMP method, the BGR method, or the like.

Thereafter, the temporary support substrate 42 and the temporaryadhesive agent 41 are removed by performing heating or light irradiationdepending on the characteristics of the temporary adhesive agent 41.

Finally, a thermal treatment may be preferably performed over atemperature range of about 100 to about 350 degrees centigrade forstabilizing an adhesive force between the support substrate 11 and thesupport substrate 10.

Next, external terminals are provided by making rewiring on the frontsurface side of the radio-frequency switch device (S350).

FIG. 19 is a cross-sectional view in a case where a rewiring insulatingfilm 47 and a metal wiring connection trench 48 are formed on the frontsurface side of the radio-frequency switch device.

Preferably, the rewiring insulating film 47 may be a silicon nitridefilm with a film thickness within a range of about 100 to about 5000 nm,and may be formed in a method such as a plasma CVD that is capable ofgenerating the film over a temperature range from room temperature toabout 300 degrees centigrade.

Following formation of the rewiring insulating film 47, the metal wiringconnection trench 48 for rewiring with a diameter within a range ofabout 5 to 100 μm is etched as far as a third metal wiring layer 24using lithography and dry etching techniques, thereby exposing the thirdmetal wiring layer 24.

FIG. 20 is a cross-sectional view showing a final form of the thirdembodiment of the present disclosure.

To achieve this final form, as a first step, a clean surface of thethird metal wiring layer 24 that is located at the bottom of the metalwiring connection trench 48 is exposed using a reverse sputtering ofargon, or any other techniques, and a titanium film with a thicknesswithin a range of about 10 to about 200 nm and a copper film 49 with athickness within a range of about 50 to about 500 nm are deposited in asputtering method or the like to form an electrode for copper plating.

Thereafter, rewiring is carried out with a line width within a range ofabout 5 to 100 μm using a lithography technique. Any region to beexcluded from the rewiring is electrically insulated with aphotosensitive organic film, such as a resist film and a film membrane,and a metallic copper film 49 is precipitated with a thickness within arange of about 1 to 10 μm in an electrolytic method to plate themetallic copper 49 at a portion to be rewired.

Further, when the photosensitive organic film formed using thelithography technique and the titanium film formed in the sputteringmethod are removed in turn utilizing a wet or dry etching technique, arewiring metal wiring layer 49 with a film thickness for rewiring withina range of about 1 to 10 μm and a line width within a range of about 5to 100 μm is formed.

Subsequently, photosensitive polyimide is coated as a rewiringprotective film 50, and a pilot hole of a solder ball 51 for a chipelectrode is drilled using the lithography technique to perform curingunder a nitrogen atmosphere for about 60 minutes over a temperaturerange of about 250 to about 300 degrees centigrade.

Finally, an organic insulating film that is formed by curing inside thepilot hole of the solder ball 51 for the chip electrode is removed inthe dry etching technique such as an oxygen plasma method, and thesolder ball 51 for the chip electrode is formed on a clean surface ofthe metallic copper 49. Such a step brings the rewiring to completion.

It is to be noted that, in the third embodiment of the presentdisclosure described thus far, the rewiring is made on the front surfaceside of the radio-frequency switch device via a contact, although aninsulating film may be formed as a protective film on the front surfaceside of the device to make rewiring through a TSV that is formed at thesupport substrate 10 side.

In the semiconductor device according to the third embodiment of thepresent disclosure that is configured in the above-described manners, itis possible to achieve the radio-frequency switch device using the SOTsubstrate similar to currently-available one by the use of the supportsubstrate 10. In the case of a shape similar to a currently-availablesubstrate, the semiconductor device according to the third embodiment ofthe present disclosure may be disadvantageous in terms of heatdissipation as compared with the semiconductor device according to thesecond embodiment of the present disclosure, although it ensures that athermal escapeway is obtained for dissipating heat arisinginstantaneously like a heat sink.

(D) Fourth Embodiment

Next, the description is provided on a fourth embodiment of the presentdisclosure. In the fourth embodiment of the present disclosure, in aradio-frequency switch device using an SOT substrate, an originalsupport substrate for the SOT substrate is also replaced with a crystaldefect introduction substrate after bonding the crystal defectintroduction substrate against the front surface of the radio-frequencyswitch device, and thereafter rewiring is made via a TSV for the crystaldefect introduction substrate at the backside of the radio-frequencyswitch device. Hereinafter, the description is provided on an example ofa manufacturing method and a structure of such a semiconductor device.

FIG. 21 is a flowchart showing a flow of a method of manufacturing thesemiconductor device according to the fourth embodiment of the presentdisclosure. FIG. 22 to FIG. 25 are each a cross-sectional view forexplaining each step of the manufacturing method illustrated in FIG. 21.Hereinafter, the description is provided along a flow of themanufacturing method illustrated in FIG. 21.

It is to be noted that, because examples of a structure and amanufacturing method using a typical SOI substrate to be used for theradio-frequency switch device after completion of a wafer process aresame with cases in FIGS. 9 and 10 that are explained in theabove-described second embodiment of the present disclosure, anycomponent parts essentially same as those of such cases according to thesecond embodiment are denoted with the same reference numerals, and thedetailed descriptions are omitted as appropriate.

In the manufacturing method shown in FIG. 21, the crystal defectintroduction substrate is bonded against the top-front surface of theradio-frequency switch device after performing steps S410 and S420similar to the steps S210 and S220 according to the above-describedsecond embodiment of the present disclosure (S430).

FIG. 22 is a cross-sectional view in a case where the support substrate11 for the SOI substrate is removed after bonding a support substrate 10a as the crystal defect introduction substrate against the front surfaceof the finished radio-frequency switch device. The support substrate 10a is same as the support substrate 10 that is fabricated in theabove-described first embodiment of the present disclosure, and isconfigured in a double layer having a crystal defect 3 a and a shallowcrystal defect 5 a, in which the crystal defect 3 a is similar to thecrystal defect 3.

FIG. 22 illustrates a state where the support substrate 10 according tothe above-described first embodiment of the present disclosure is bondedagainst the top-front surface of the radio-frequency switch device usinga first adhesive agent 61. It is to be noted that FIG. 22 shows asupport substrate removal area 62 of the SOI substrate at a locationwhere the support substrate 11 is removed.

Preferably, the first adhesive agent 61 in use for bonding may have acapability of permanently bonding the support substrate 10 with theradio-frequency switch device, as well as a dielectric tangent (tan δ)of the radio-frequency characteristics within a range of about 0.0001 toabout 0.01 and a film thickness within a range of about 50 to about 1000nm, and a candidate example for such an adhesive agent may includesiloxane-based benzocyclobutene (BCB). After bonding of the supportsubstrate 10, an adhesive force may be preferably stabilized byperforming a thermal treatment over a temperature range of about 100 toabout 350 degrees centigrade.

It is to be noted that, in this fourth embodiment of the presentdisclosure, the support substrate 10 is bonded with the radio-frequencyswitch device using the first adhesive agent 61, although a bondingmethod is not limited thereto, but a direct bonding without using anadhesive agent may be also permitted after planarizing the front surfaceby performing a polishing work in the CMP method or the BGR method.

It is possible to remove the support substrate 11 for the SOI substrateby a polishing work in the CMP method, a grinding work in the BGRmethod, or a wet etching process using a chemical solution such as anitric fluoride-based solution. At this stage, the box layer 12 on theSOI substrate at the backside of the device is exposed.

Subsequently, the support substrate 11 as an original support substrateis replaced with a support substrate 10 b as a crystal defectintroduction substrate (S440).

The support substrate 10 b of the fourth embodiment is manufacturedusing the method of manufacturing a semiconductor device according tothe above-described first embodiment of the present disclosure. Inparticular, the crystal defect 3 b in the support substrate 10 b issimilar to the crystal defect 3 in FIG. 3. The crystal defect 3 b isformed using the method according to the above-described firstembodiment of the present disclosure. The shallow crystal defect 5 b issimilar to the shallow crystal defect 5 in FIGS. 4 and 5. The shallowcrystal defect 5 b is formed using the method according to theabove-described first embodiment of the present disclosure. FIG. 23 is across-sectional view in a case where the support substrate 11 isreplaced with the support substrate 10 b. The support substrate 10 b ispermanently bonded against the box layer 12 at the backside of theradio-frequency switch device using a second adhesive agent 63. However,a method of bonding the box layer 12 and the support substrate 10 b isnot limited thereto, but, for example, direct bonding using a plasmamethod or any other techniques may be also permitted after exposure ofthe box layer 12.

As with the first adhesive agent 61, for ensuring permanent bonding, thesecond adhesive agent 63 in use for bonding may preferably havedielectric tangent (tan δ) of the radio-frequency characteristics withina range of about 0.0001 to about 0.01 and a film thickness within arange of about 50 to about 1000 nm, and a candidate example for such anadhesive agent may include siloxane-based benzocyclobutene (BCB).Subsequently, a thermal treatment may be preferably performed over atemperature range of about 100 to about 350 degrees centigrade forstabilizing an adhesive force.

Thereafter, external terminals are provided by making rewiring from theside of the crystal defect introduction substrate that is replaced withthe original support substrate for the SOI substrate (S450).

FIG. 24 is a cross-sectional view in a case where a TSV 64 for metalwiring connection and a rewiring insulating film 65 are formed from thesupport substrate 10 b side after replacing the support substrate 11with the support substrate 10 b.

To form such a shape, to start with, the TSV 64 for metal wiringconnection with a diameter within a range of about 5 to 100 μm is formedby etching as far as the first metal wiring layer 20 using lithographyand dry etching techniques to expose the first metal wiring layer 20.

Next, to form an electrically insulating film for the support substrate10 b, the rewiring insulating film 65 is formed with a thickness withina range of about 100 nm to 20 μm using a plasma CVD method and the likethat allow to form a film over a temperature range from room temperatureto about 300 degrees centigrade.

Because the rewiring insulating film 65 is formed on the front surfaceof the first metal wiring layer 20 at the bottom of the TSV 64 for metalwiring connection as well, when a whole-area etch back is carried outusing the dry etching technique such as RIE (Reactive Ion Etching), therewiring insulating film 65 that is formed on the front side of thefirst metal wiring layer 20 is etched, and a structure is formed wherethe rewiring insulating film 65 with a thickness within a range of about50 to 10 μm is selectively left on a sidewall of the TSV 64 for metalwiring connection.

FIG. 25 is a cross-sectional view showing a final form of thesemiconductor device according to the fourth embodiment of the presentdisclosure. To achieve this final form, as a first step, a clean surfaceof the first metal wiring layer 20 that is located at the bottom of theTSV 64 for metal wiring connection is exposed using a reverse sputteringof argon, or any other techniques, and a titanium film with a thicknesswithin a range of about 10 to about 200 nm and a copper film 66 with athickness within a range of about 50 to about 500 nm are deposited in asputtering method or the like to form an electrode for copper plating.

Thereafter, rewiring is carried out with a line width within a range ofabout 5 to 100 μm using a lithography technique. Any region to beexcluded from the rewiring is electrically insulated with aphotosensitive organic film, such as a resist film and a film membrane,and a metallic copper film 66 is precipitated with a thickness within arange of about 1 to 10 μm in an electrolytic method to plate themetallic copper 66 at a portion to be rewired.

Further, when the photosensitive organic film formed using thelithography technique and the titanium film formed in the sputteringmethod are removed utilizing a wet or dry etching technique, a rewiringmetal wiring layer 66 with a film thickness for rewiring within a rangeof about 1 to 10 μm and a line width within a range of about 5 to 100 μmis formed.

Subsequently, photosensitive polyimide is coated as a rewiringprotective film 67, and a pilot hole of a solder ball 68 for a chipelectrode is drilled using the lithography technique to perform curingunder a nitrogen atmosphere for about 60 minutes over a temperaturerange of about 250 to about 300 degrees centigrade.

Finally, an organic insulating film that is formed by curing inside thepilot hole of the solder ball 68 for the chip electrode is removed inthe dry etching technique such as an oxygen plasma method, and thesolder ball 68 for the chip electrode is formed on a clean surface ofthe metallic copper 66. Such a step brings the rewiring to completion.

It is to be noted that, in this embodiment of the present disclosure,the rewiring is made via the TSV from the side of the support substrate10 b that is bonded against the back surface side of the radio-frequencyswitch device, although the rewiring may be made via the TSV from theside of the support substrate 10 a that is bonded against the frontsurface side of the radio-frequency switch device.

In the semiconductor device according to the fourth embodiment of thepresent disclosure that is fabricated in the above-described manners,because the support substrate 10 is bonded against both sides of asemiconductor layer where the radio-frequency switch device is formed,two heat dissipation paths are assured, which is more advantageous inthe heat dissipation effect as compared with the above-described secondand third embodiments of the present disclosure.

(E) Fifth Embodiment

FIG. 26 illustrates an example of an RF (Radio Frequency) module (aradio-frequency module, or an “antenna switch module”) 100 according toa fifth embodiment of the present disclosure. The RF module 100 isprovided with an IC (Integrated Circuit) 300. The IC 300 is mounted withthe SOI substrate and the radio-frequency switch device. The SOIsubstrate includes any one of the support substrates 10, 10 a, and 10 baccording to the first embodiment to the fourth embodiment describedabove. The RF module 100 is provided, in addition to the IC 300, with aDCDC converter 200 and an FEM (Front End Module) 400. The DCDC converter200 provides each of the IC 300 and the FEM 400 with a voltage. The IC300 includes a switch SW and a logic circuit 301 that controls theswitch SW. In the IC 300, the switch SW receives a wireless signal froman antenna ANT, and selects an RF signal. The FEM 400 includes an IPD(Intelligent Power Device) 401 and an inverter 402, and amplifies the RFsignal selected in the IC 300. For example, the IPD 401 may be anelement such as a diode. The signal output from the FEM 400 is suppliedto a signal processing section 500 to be converted into a digitalsignal. The signal processing section 500 may include various ICs suchas an RF section and a BB (Base Band) section. It is to be noted that,in the fifth embodiment, the radio-frequency switch device that utilizesthe SOI substrate is applied to a receiver module, although thetechnology is not limited thereto. In one embodiment, theradio-frequency switch device that utilizes the SOI substrate describedabove may be applied to a transmitter module.

(F) Summary of Example Embodiments

According to the second to fourth embodiments of the present disclosurethat are described thus far, in the semiconductor device having theradio-frequency switch device on the SOI substrate, the crystal defect 3as a first kind of crystal defect is formed uniformly over a wholesurface of the support substrate 10 for the SOI substrate. As a result,this makes it possible to prevent any thermal destruction due toself-heating of MOSFETs in antenna switches to be formed on the SOIsubstrate for controlling high power outputs for radio frequencies,while maintaining excellent harmonic distortion characteristics. Also,according to the fifth embodiment of the present disclosure, theradio-frequency module is mounted with the radio-frequency switch devicethat utilizes the SOI substrate described above. As a result, this makesit possible to achieve a radio-frequency module having higherreliability.

It is to be noted that the present technology is not limited to theabove-described embodiments and modification examples, but it alsoencompasses a configuration where each configuration disclosed in theabove-described embodiments and modification examples is replaced witheach other or combination thereof is changed, a configuration where eachconfiguration disclosed in a known technology as well as theabove-described embodiments and modification examples is replaced witheach other or combination thereof is changed, and the like. Further, atechnical scope of the present technology is not limited to theabove-described embodiments, but it covers elements described in claimsand equivalents thereof.

Furthermore, the technology encompasses any possible combination of someor all of the various embodiments described herein and incorporatedherein.

It is possible to achieve at least the following configurations from theabove-described example embodiments of the disclosure.

(1) A semiconductor device, including:

a silicon-on-insulator substrate including a support substrate, thesupport substrate including a first crystal defect having a uniformdensity all over the support substrate; and

a radio-frequency switch device provided on the silicon-on-insulatorsubstrate.

(2) The semiconductor device according to (1), wherein a region otherthan the support substrate does not include the first crystal defect.(3) The semiconductor device according to (1) or (2), wherein thesupport substrate is bonded through adhesive attachment with asemiconductor layer that includes an element layer and a wiring layer,the element layer being provided with the radio-frequency switch device,and the wiring layer being provided with a metallic wire.(4) The semiconductor device according to (3), wherein theradio-frequency switch device is provided in the semiconductor layer inproximity to a surface of the semiconductor layer, the surface being onan opposite side of a surface, of the semiconductor layer, in contactwith the support substrate.(5) The semiconductor device according to (3), wherein theradio-frequency switch device is provided in the semiconductor layer inproximity to a surface, of the semiconductor layer, in contact with thesupport substrate.(6) The semiconductor device according to (3), wherein the supportsubstrate is bonded through the adhesive attachment on both sides of thesemiconductor layer.(7) The semiconductor device according to any one of (3) to (6), whereinrewiring is made for the semiconductor layer from a surface, of thesemiconductor layer, close to the radio-frequency switch device.(8) The semiconductor device according to any one of (3) to (6), whereinrewiring is made for the semiconductor layer from a surface, of thesemiconductor layer, far from the radio-frequency switch device.(9) The semiconductor device according to any one of (3) to (8), whereinrewiring is made for the semiconductor layer via a through-silicon viathat runs through the support substrate to the semiconductor layer.(10) The semiconductor device according to any one of (1) to (9),wherein the support substrate includes a crystal defect layer on a side,of the support substrate, bonded with the semiconductor layer, thecrystal defect layer including a second crystal defect.(11) The semiconductor device according to (10), wherein the secondcrystal defect of the crystal defect layer is provided, through an ionimplantation of one of inert gas, carbon, and silicon, in a depth rangeof about 100 nm to several micrometers from a surface on the side bondedwith the semiconductor layer.(12) The semiconductor device according to any one of (1) to (11),wherein the first crystal defect of the support substrate is providedthrough irradiation of an electron beam and has a range of the densityof about 1×10¹⁴ pieces/cubic centimeter to about 1×10¹⁶ pieces/cubiccentimeter.(13) The semiconductor device according to any one of (1) to (12),wherein the support substrate includes a substrate in which the firstcrystal defect is provided on a silicon substrate having an oxygenconcentration within a range of about 1×10¹⁵ atoms/cubic centimeter toabout 1×10¹⁷ atoms/cubic centimeter, having a specific resistance withina range of about 100 Ωcm to about 1×10⁵ Ωcm, and being manufactured inan floating zone method, or includes a substrate in which the firstcrystal defect is provided on a silicon substrate having a specificresistance within a range of about 100 Ωcm to about 1×10⁵ Ωcm and inwhich silicon is epitaxially grown on a substrate manufactured in aCzochralski method or an magnetic-field-applied Czochralski method.(14) An antenna switch module, including the semiconductor deviceaccording to any one of (1) to (13).(15) A method of manufacturing a semiconductor device, the methodincluding:

forming a semiconductor layer on a silicon-on-insulator substratethrough laminating an element layer and a wiring layer in sequence onthe silicon-on-insulator substrate, the element layer including aradio-frequency switch device, and the wiring layer including a metalwire;

fabricating a crystal defect introduction substrate formed with a firstcrystal defect having a uniform density all over the crystal defectintroduction substrate; and

bonding the fabricated crystal defect introduction substrate with asurface of the semiconductor layer through adhesive attachment.

(16) The method of manufacturing the semiconductor device according to(15), wherein, in the bonding the fabricated crystal defect introductionsubstrate, an original support substrate of the silicon-on-insulatorsubstrate is removed after the crystal defect introduction substrate isbonded with the surface, on a wiring layer side, of the semiconductorlayer through the adhesive attachment.(17) The method of manufacturing the semiconductor device according to(15), wherein, in the bonding the fabricated crystal defect introductionsubstrate,

an original support substrate of the silicon-on-insulator substrate isremoved after a temporary support substrate is bonded with the surface,on a wiring layer side, of the semiconductor layer through the adhesiveattachment,

the crystal defect introduction substrate is bonded, instead of theoriginal support substrate, with the surface, on an element layer side,of the semiconductor layer through the adhesive attachment, and

the temporary support substrate is then removed.

(18) The method of manufacturing the semiconductor device according to(15), wherein, in the bonding the fabricated crystal defect introductionsubstrate,

an original support substrate of the silicon-on-insulator substrate isremoved after bonding the crystal defect introduction substrate with thesurface, on a wiring layer side, of the semiconductor layer through theadhesive attachment, and

the crystal defect introduction substrate is bonded, instead of theoriginal support substrate, also with the surface, on an element layerside, of the semiconductor layer through the adhesive attachment.

(19) The method of manufacturing the semiconductor device according to(15), wherein, in the bonding the fabricated crystal defect introductionsubstrate,

an original support substrate of the silicon-on-insulator substrate isremoved after bonding a temporary support substrate with the surface, ona wiring layer side, of the semiconductor layer through the adhesiveattachment,

the crystal defect introduction substrate is bonded, instead of theoriginal support substrate, with the surface, on an element layer side,of the semiconductor layer through the adhesive attachment, and

the crystal defect introduction substrate is also bonded with thesurface, on the wiring layer side, of the semiconductor layer throughthe adhesive attachment.

[1] A semiconductor device having a radio frequency switch, thesemiconductor device comprising:a metal wiring insulating film bonded to a silicon substrate; andcrystal defects throughout the silicon substrate; anda first crystal defect layer extending into the silicon substrate from asurface of the silicon substrate, crystal defects formed throughout thefirst crystal defect.[2] The semiconductor device according to [1], further comprising:oxygen throughout the silicon substrate, a concentration of the oxygenin the silicon substrate being within a range of about 1×1015 to about1×1017 atoms/cubic centimeter.[3] The semiconductor device according to [1] or [2], furthercomprising:ions of an inert gas within the first crystal defect layer.[4] The semiconductor device according to any one of [1] to [3], furthercomprising:an adhesive agent configured to bond the surface of the siliconsubstrate to the metal wiring insulating film, the adhesive agent beingbetween the first crystal defect layer and the metal wiring insulatingfilm.[5] The semiconductor device according to any one of [1] to [4], whereinthe metal wiring insulating film is between the silicon substrate and asupport substrate, the support substrate being a material from the groupconsisting of silicon, ceramic, and quartz.[6] The semiconductor device according to any one of [1] to [5], furthercomprising:a metallic copper film touching a first metal wiring layer, the firstmetal wiring layer and a second metal wiring layer being in the metalwiring insulating film.[7] The semiconductor device according to [6], further comprising:a metal wiring connection plug between the first metal wiring layer andthe second metal wiring layer, the metal wiring connection plug touchingthe first metal wiring layer and the second metal wiring layer.[8] The semiconductor device according to [7], further comprising:a rewiring insulating film between the metal wiring insulating film anda rewiring protective film, a portion of the metallic copper film beingbetween the rewiring protective film and the rewiring insulating film.[9] The semiconductor device according to [8], further comprising:a solder ball extending through the rewiring protective film, theportion of the metallic copper film touching the solder ball.[10] The semiconductor device according to any one of [1] to [9],further comprising:an element separation layer between a buried oxide layer and the metalwiring insulating film, drain and source electrodes of a transistorbeing within the element separation layer.[11] The semiconductor device according to [10], wherein the buriedoxide layer is between the rewiring insulating film and the elementseparation layer.[12] The semiconductor device according to [10] or [11], wherein theburied oxide layer is between the first crystal defect layer and theelement separation layer.[13] The semiconductor device according to any one of [1] to [12],further comprising:a second crystal defect layer within the silicon substrate, the secondcrystal defect layer being between the metal wiring insulating film andthe first crystal defect layer.[14] The semiconductor device according to [13], wherein the secondcrystal defect layer extends from the surface of the silicon substrateinto the first crystal defect layer, the first crystal defect layerdiffering from the second crystal defect layer.[15] The semiconductor device according to [13] or [14], wherein thefirst crystal defect layer extends from the second crystal defect layerto an opposite surface of the silicon substrate.[16] An antenna switch module comprising:the semiconductor device according to any one of [1] to [15];an integrated circuit mounted with the radio-frequency switch device andthe silicon substrate.[17] A method of manufacturing a semiconductor device, the methodcomprising: forming crystal defects throughout a silicon substrate,radiation or a diffusion being used to form the crystal defects, andthereafter;implanting ions into a surface of the silicon substrate to form acrystal defect layer, the crystal defect layer extending from thesurface of the silicon substrate into the crystal defects.[18] The method according to [17], wherein the radiation is from thegroup consisting of electron beam irradiation, gamma ray radiation, andneutron ray radiation.[19] The method according to [17] or [18], wherein a heavy-metalmaterial is diffused during the diffusion.[20] The method according to any one of [17] to [19], wherein a processto grow or fabricate the silicon substrate is from the group consistingof a Floating Zone method, a Czochralski method, and aMagnetic-Field-applied Czochralski method.[21] The method according to any one of [17] to [20], wherein aconcentration of oxygen within the silicon substrate is about 1×1015 toabout 1×1017 atoms/cubic centimeter, the silicon substrate having ofabout 100 to about 1×105 Ωcm.[22] The method according to any one of [17] to [21], furthercomprising: bonding the crystal defect layer to a metal wiringinsulating film, first and second metal wiring layers being in the metalwiring insulating film.[23] The method according to [22], further comprising:forming a metal wiring connection trench through a rewiring insulatingfilm, the metal wiring connection trench terminating at the first metalwiring layer.[24] The method according to [23], further comprising:depositing a metallic copper film into the metal wiring connectiontrench, the metallic copper film touching the first metal wiring layer.[25] The method according to [24], further comprising:forming a rewiring protective film on the rewiring insulating film, aportion of the metallic copper film being between the rewiringprotective film and the rewiring insulating film.[26] The method according to [24] or [25], wherein a support substrateis between the metal wiring insulating film and the rewiring insulatingfilm, another silicon substrate being the support substrate.[27] The method according to [26], wherein other crystal defects arethroughout the support substrate, another crystal defect layer extendingfrom the surface of the support substrate into the other crystaldefects.[28] The method according to any one of [24] to [27], furthercomprising: forming a pilot hole through the rewiring protective film,the pilot hole exposing the portion of the metallic copper film.[29] The method according to [28], further comprising:depositing a solder ball in the pilot hole, the portion of the metalliccopper film touching the solder ball.

The present disclosure contains subject matter related to that disclosedin Japanese Priority Patent Application JP 2012-245161 filed in theJapan Patent Office on Nov. 7, 2012, the entire content of which ishereby incorporated by reference.

It should be understood by those skilled in the art that variousmodifications, combinations, sub-combinations, and alterations may occurdepending on design requirements and other factors insofar as they arewithin the scope of the appended claims or the equivalents thereof.

What is claimed is:
 1. A semiconductor device, comprising: asilicon-on-insulator substrate; a radio-frequency switch device providedon the silicon-on-insulator substrate; and a support substrate providedover a surface of the radio-frequency switch device, the supportsubstrate including first crystal defect; and wherein a part of thesilicon-on insulator substrate changes to other substrate includingsecond crystal defect.
 2. The semiconductor device according to claim 1,wherein the support substrate is bonded through adhesive attachment withthe silicon-on-insulator substrate that includes an element layer and awiring layer, the element layer being provided with the radio-frequencyswitch device, and the wiring layer being provided with a metallic wire.3. The semiconductor device according to claim 2, wherein theradio-frequency switch device is provided in the silicon-on-insulatorsubstrate in proximity to a surface of the silicon-on-insulatorsubstrate, the surface being on an opposite side of a surface, of thesilicon-on-insulator substrate, in contact with the support substrate.4. The semiconductor device according to claim 2, wherein theradio-frequency switch device is provided in the silicon-on-insulatorsubstrate in proximity to a surface, of the silicon-on-insulatorsubstrate, in contact with the support substrate.
 5. The semiconductordevice according to claim 2, wherein the support substrate is bondedthrough the adhesive attachment on both sides of thesilicon-on-insulator substrate.
 6. The semiconductor device according toclaim 2, wherein rewiring is made for the silicon-on-insulator substratefrom a surface, of the silicon-on-insulator substrate, close to theradio-frequency switch device.
 7. The semiconductor device according toclaim 2, wherein rewiring is made for the silicon-on-insulator substratefrom a surface, of the silicon-on-insulator substrate, far from theradio-frequency switch device.
 8. The semiconductor device according toclaim 2, wherein rewiring is made for the silicon-on-insulator substratevia a through-silicon via.
 9. The semiconductor device according toclaim 1, wherein the first crystal defect is provided, through an ionimplantation of one of inert gas, carbon, and silicon, in a depth rangeof about 100 nm to several micrometers from a surface on the side bondedwith the semiconductor layer.
 10. The semiconductor device according toclaim 1, wherein the first crystal defect of the support substrate isprovided through irradiation of an electron beam and has a range of thedensity of about 1×1014 pieces/cubic centimeter to about 1×1016pieces/cubic centimeter.
 11. The semiconductor device according to claim1, wherein the support substrate comprises a substrate in which thefirst crystal defect is provided on the silicon substrate having anoxygen concentration within a range of about 1×1015 atoms/cubiccentimeter to about 1×1017 atoms/cubic centimeter, having a specificresistance within a range of about 100 Ωcm to about 1×105 Ωcm, and beingmanufactured in an floating zone method, or comprises a substrate inwhich the first crystal defect is provided on a silicon substrate havinga specific resistance within a range of about 100 Ωcm to about 1×105 Ωcmand in which silicon is epitaxially grown on a substrate manufactured ina Czochralski method or an magnetic-field-applied Czochralski method.12. An antenna switch module provided with a semiconductor device, thesemiconductor device comprising: a silicon-on-insulator substrate; aradio-frequency switch device provided on the silicon-on-insulatorsubstrate; and a support substrate provided over a surface of theradio-frequency switch device, the support substrate including a firstcrystal defect; and wherein a part of the silicon-on insulator substratechanges to another substrate including a second crystal defect.
 13. Theantenna switch module according to claim 12, wherein a region other thanthe support substrate does not include a crystal defect layer.
 14. Theantenna switch module according to claim 12, wherein the supportsubstrate is bonded through adhesive attachment with thesilicon-on-insulator substrate that includes an element layer and awiring layer, the element layer being provided with the radio-frequencyswitch device, and the wiring layer being provided with a metallic wire.15. The antenna switch module according to claim 14, wherein theradio-frequency switch device is provided in the silicon-on-insulatorsubstrate in proximity to a surface of the silicon-on-insulatorsubstrate, the surface being on an opposite side of a surface, of thesilicon-on-insulator substrate, in contact with the support substrate.16. The semiconductor device according to claim 14, wherein theradio-frequency switch device is provided in the silicon-on-insulatorsubstrate in proximity to a surface, of the silicon-on-insulatorsubstrate, in contact with the support substrate.
 17. The semiconductordevice according to claim 14, wherein the support substrate is bondedthrough the adhesive attachment on both sides of thesilicon-on-insulator substrate.
 18. The semiconductor device accordingto claim 16, wherein rewiring is made for the silicon-on-insulatorsubstrate from a surface, of the silicon-on-insulator substrate, closeto the radio-frequency switch device.
 19. The semiconductor deviceaccording to claim 12, wherein rewiring is made for thesilicon-on-insulator substrate from a surface, of thesilicon-on-insulator substrate, far from the radio-frequency switchdevice.
 20. The semiconductor device according to claim 12, whereinrewiring is made for the silicon-on-insulator substrate via athrough-silicon via.
 21. The semiconductor device according to claim 12,wherein the first crystal defect is provided, through an ionimplantation of one of inert gas, carbon, and silicon, in a depth rangeof about 100 nm to several micrometers from a surface on the side bondedwith the semiconductor layer.
 22. The semiconductor device according toclaim 12, wherein the crystal defect of the support substrate isprovided through irradiation of an electron beam and has a range of thedensity of about 1×1014 pieces/cubic centimeter to about 1×1016pieces/cubic centimeter.
 23. The semiconductor device according to claim12, wherein the support substrate comprises a substrate in which thecrystal defect is provided on the silicon substrate having an oxygenconcentration within a range of about 1×1015 atoms/cubic centimeter toabout 1×1017 atoms/cubic centimeter, having a specific resistance withina range of about 100 Ωcm to about 1×105 Ωcm, and being manufactured inan floating zone method, or comprises a substrate in which the firstcrystal defect is provided on a silicon substrate having a specificresistance within a range of about 100 Ωcm to about 1×105 Ωcm and inwhich silicon is epitaxially grown on a substrate manufactured in aCzochralski method or an magnetic-field-applied Czochralski method.